Swimming pool filter systems generally include a filter pump and a filter, such as a sand filled tank, DE filter, etc. a two-position push-pull valve is included to switch the system between a filtering mode and a backwash mode of operation. In the filtering mode of operation, water is pumped from the pool and directed through the filter in a filtering direction and the filtered water is directed back into the pool. When enough foreign matter accumulates in the filter to reduce the pumping action, the filter is backwashed, i.e., water is directed from the pool through the filter in the opposite direction and then into a drain or other waste-water receptacle. Generally, a filter can be cleaned by backwashing for several minutes. The system is then switched back into the filtering mode.
Periodically, the pool is cleaned by vacuuming the bottom and sides to remove any accumulated foreign materials that are not otherwise drawn into the filtering system. To perform this task one end of a hose is inserted into the drain in the skimmer and the other end is moved across the bottom and sides of the pool to draw any foreign materials into the filtering system. During vacuuming the filter system is simply operated in the filter mode. When the vacuuming is completed the filtering system is moved into the backwash mode and when the backwash is completed the filter is moved into the filtering mode.
A problem arises with this system when relatively large amounts of foreign materials, e.g. dust, leaves, etc., is blown into the pool. When large amounts of foreign materials are present in a pool, it may not be possible to completely clean the pool with one vacuuming. The filter may become so clogged with foreign material that the vacuum drops to near zero and little or no additional material can be removed from the pool. In such cases the vacuuming hose must be removed from the skimmer and a backwashing cycle must be performed. The vacuuming hose is then reinserted, a vacuum is established and the cleaning can proceed. In some instances this procedure needs to be repeated several times, which is laborious and time consuming. Also, during the repetitions, dirt and other foreign material can reenter the pool from the vacuuming hose, the filter, etc. In addition, fine dirt particles (e.g. dust and the like) can pass right through many of the popular filters, such as sand filters, and simply be returned to the pool. Thus, the vacuuming process can be inefficient, time consuming, and frustrating.
It would be highly advantageous, therefore, to remedy the foregoing and other deficiencies inherent in the prior art.
Accordingly, it is an object of the present invention to provide a new and improved modified push-pull valve for filtering systems and the like.
It is another object of the present invention to provide a new and improved modified plunger to convert push-pull valves into three mode operation, i.e. filtering mode, backwash mode, and direct flow to drain mode.
Another object of the invention is to provide a new and improved modified push-pull valve that is relatively inexpensive and easy to install and operate.
Another object of the invention is to provide a new and improved modified push-pull valve and method of operation that can substantially simplify and improve the filtering operation.
Another object of the invention is to provide a new and improved modified push-pull valve that can be adapted to most of the filtering systems without additional cost or special equipment.